options/config management basically working

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@2520 fd906abe-77d9-0310-91a1-e0d9ade77398

meta/README.txt

@@ -23,6 +23,9 @@ be created as elements within the Options object.
   >>> config.i18n.languages
   ['de', 'en', 'it']
 
+  >>> config('i18n.languages')
+  ['de', 'en', 'it']
+
 Loading options as Python code
 ------------------------------
 

meta/config.py

@@ -22,8 +22,10 @@ Basic implementations for configuration options
 $Id$
 """
 
+import os
 from zope.interface import implements
 
+from cybertools.meta.element import Element
 from cybertools.meta.interfaces import IOptions, IConfigurator
 from cybertools.meta.namespace import AutoNamespace, Executor, ExecutionError
 
@@ -32,6 +34,30 @@ class Options(AutoNamespace):
 
     implements(IOptions)
 
+    def __call__(self, key, default=None):
+        value = self
+        for part in key.split('.'):
+            value = getattr(value, part)
+        if isinstance(value, Element):
+            value = default
+        return value
+
+
+class GlobalOptions(Options):
+
+    _filename = None
+    _lastChange = None
+
+    def __call__(self, key, default):
+        if self._filename is not None:
+            fn = self._filename
+            if os.path.exists(fn):
+                modified = os.path.getmtime(fn)
+                if self._lastChange is None or self._lastChange < modified:
+                    Configurator(self).load(file=fn)
+                    self._lastChange = modified
+        return super(GlobalOptions, self).__call__(key, default)
+
 
 class Configurator(object):
 

meta/element.py

@@ -73,7 +73,7 @@ class Element(dict):
         return result
 
     def __setattr__(self, key, value):
-        if key in self.realAttributes:
+        if key in self.realAttributes or key.startswith('_'):
             super(Element, self).__setattr__(key, value)
         else:
             self[key] = value
@@ -116,6 +116,8 @@ class AutoElement(Element):
     typeName = 'AutoElement'
 
     def __getattr__(self, key):
+        if key.startswith('_'):     # no auto-creation for special attributes
+            raise AttributeError(key)
         result = self.get(key, _not_found)
         if result is _not_found:
             result = self.children.get(key, _not_found)

meta/interfaces.py

@@ -31,27 +31,24 @@ class IOptions(Interface):
         a file.
     """
 
-    def __contains__(key):
-        """ Return True if this object provides the option identified
-            by the key given.
-        """
+    def __call__(key):
+        """ Return the value belonging to the key given. The key may be a
+            dotted name - it will be splitted on dots and attributes
+            will be looked up in turn on the resulting objects.
 
-    def __iter__():
-        """ Return an iterator over the option keys provided by this
-            object.
-        """
+            Return None if no corresponding setting can be found.
 
-    def values():
-        """ Return an iterator over all settings.
+            The method may also provide some fallback mechanism when
+            the element is not defined in the current object.
         """
 
     def __getitem__(key):
-        """ Return the value belonging to the key given.
+        """ Return the value belonging to the key given. The key
+            must not contain dots.
         """
 
     def __getattr__(key):
-        """ Return the value belonging to the key given
-            (same as ``__getitem__()``).
+        """ Return the value belonging to the key given.
         """
 
     def __str__():

meta/namespace.py

@@ -87,6 +87,8 @@ class AutoNamespace(BaseNamespace):
         return result
 
     def __getattr__(self, key):
+        if key.startswith('_'):     # no auto-creation for special attributes
+            raise AttributeError(key)
         return self[key]